Jerkwise-acting driving device for ignition apparatus



June 10 1924. 3,497,328

0. FISCHER JERKWISE ACTING DRIVING DEVICE FOR IGNITION APPARATUS Filed Oct. 2'7. 192).

Patented June lfl,

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' Application filed heat r- 2?, 192;. Serial in. mm; i a

T0. all whom it may concern: 5 i

;Bef 1t known that I, O'r'ro Frsonnn, a c1tizen of-Ge'rmany, residing at stuttgartyGere many, have invented certain new and useful 5 Improvements 111 a Jerkw1se-Act1 ng,DrivingDevice for Ignition Apparatus, of which th'efollowingis a specification.

- "This. invention relates ,1n general to drivmg devices for ,1gn1t1on apparatus of the kind'in whichajerk-wise motion of thev armature isefiected by a temporary locking of a coupling-half. This motion is given such a speed that the generation of an igni tion spark isassured, sothat the ignition canybez effected evenat slow speed of the engine. Discontinuing the jerk-wise motion is automatically effected by centrifugal power at a certain higher number offrevolu tions. A spring which had been put under tension on looking the respective coupling half and then produced the jerk-wise motion serves thereafter as a dragging coupling between the two halves of the driving device. I

Now, concerning the known devices of this kind there is that drawback connected with them that they can be employed only for one direction of motion. This drawback is obviated in and by the present invention, the gist of which consists in the parts effecting the release at the temporary locking serving also as abutments for the dragging coupling at normal running of the engine. Besides the possibility of employing the same model for rotation to the right, as well as to the left, without a change of the details, the further advantage of a greater simplicity of the apparatus is attained.

In order to make my invention clearer, I refer to the accompanying drawing, in which similar letters of reference denote similar parts throughout the several views, and in which Figure 1 is a front view of a device; Figure 2 is a similar illustration showing the same parts in another position;

and Figure 3 is a side view, one of the 0011- connected with each other by a spring f; one endof which is attached ;to{a;projectionq of the'half mend the 'other end of which is at tached to a projection r ofthe'jha'lf Z). The ob ectsof this spring are; firstly, to" drag the coupling half, I) which is that retained by the" temporary locking sufliciently quickly:

after it has been released; secondlyfto bring the couplingfhalves indirect contact with each other at normal running of the ignition apparatus. 2 i V The coupling half 6 carries leversg which are supported in stays p and are eccentrr cally mounted with respect to the shaft Z and movable upon bolts 'jn The levers have lugs which co-operate withta'n abut ment mof the casing in of the ignition a' paratus, and. each has atlfthe inner side of its end a curved surface a which co-operates with a projection 0 provided on the coupling half and serving for releasing the levers at the temporary locking.

The manner of operation of this device is as follows:

When at rest, the various parts are in the position shown in Fig. 1. The projections 0 are in direct and intimate contact with the stays p owing to the tension or pull of the spring 7. When at slow running of the ignition apparatus the lug z of a lever g. contacts with the abutment n, the coupling half 7) is held fast. whereas the half a con tinues its rotation under the influence of the driving power. thus putting the spring f under tension. When lefthand projection 0 of the half a contacts with the curved surfaces of the lefthand (upper) lever g (Fig. 2), this lever is lifted until its lug i disengages the associate abutment m, whereby the coupling half 7) is caused to suddenly follow the coupling half a, under the pull of the spring 7". until the projections 0 again contact with the stays p. This is repeated until the internal combustion engine has commenced to start and the speed of the ignition apparatus has become so great that the levers g are flung outwards under the centrifugal power then arising.

From this moment the levers g are out of engagement with the abutment m can therefore no longer function to hold or stop the coupling half I). The two halvesa and b arenow connectedwith each other by a drag-coupling in that the abutments 0 lie close to the stays 9 under the action of the spring and remain in this position during the normal running of the engine. This arrangement, it is to be observed, prevents an overrunning of the driven part of the magneto with respect to the driving part during the normal running of the engine such as might otherwise occur by momentum of the driven part of the magneto when the speed of the engine and hence the speed of rotation of the driving part for the magneto is reduced.

In order to employ the arrangement also for the other direction, the only alterations necessaryare, firstly, to take the levers 9 off their pivots it, turn each of them so as to make it point to the opposite direction, and replace it upon its pivot; secondly, to mount the spring f in the opposite direction about the periphery of the parts a and Z) so' as to make it draw the projections o against the other side of the stays p.

The special construction of the various parts entering into the combination shown anddescribed by way of example is not an essential characteristic of the invention. There may be changes of the construction without change of the efl'ect. The coiled spring" shown may, for instance be replaced by anotherkind or configuration of spring,

and instead of the levers 9 ball or other fly masses may be made use of.

Having now described my invention, what I desire to secure by a patent of the United States is:

A jerk-wise acting driving device for ignition apparatus comprising, in combination, a driven coupling part, a driving coupling disc, a springxc-onnectingthe said coupling part and the said coupling'disc, spaced stays on the said'coupling part, levers pivoted on the said stays and extending into the space therebetween, a fixed abutment on the ignition apparatus adapted to engage said levers in locking position to hold said coupling part immovable, projections from said coupling disc extending into the space betweensaid stays and adapted in one driving movementof'said disc to'disengagesaid levers from saidlockingpositiom'said spring being adapted to hold said coupling part in driven relation withsaid disc during the further driving movement of said disc'and with 'saidprojections and stays in contact. In testimony whereof I have affixed *my signature in presence of two witnesses.

I; "OTTO FISCHER Witnesses: R FF IEDA KLAIBER,

E. SCHLEIGHER. 

